A touchscreen embedded in an electronic device such as a smartphone receives a touch input. The touchscreen may exist in various forms. For example, a capacitive touchscreen uses static electricity or a particular electric current flowing in a human body, and a resistive touchscreen uses pressure. Other types of touchscreens such as an electromagnetic induction touchscreen, an ultrasonic touchscreen and an infrared touchscreen are also being used.
A capacitive touchscreen has a function called multi-touch. When multiple points on the touchscreen are touched simultaneously, multi-touch enables the touchscreen to recognize the points simultaneously. If multi-touch is used, various patterns formed using multi-touched points can be input to an electronic device such as a smartphone. Of the various patterns, only different types of patterns that are distinguished from each other can be used as identification marks.